Vehicular ad hoc network (VANET) is a promising component to enable a wide range of mobile distributed applications in order to improve the safety and efficiency of vehicle transportation. In VANETs, vehicles communicate either with each other via vehicle-to-vehicle (V2V) communication or with stationary road side infrastructure or road side units (RSUs) via vehicle-to-infrastructure (V2I) communication, to exchange information generated by the mobile applications. Thus, vehicles communicate via a radio channel to exchange messages primarily to support applications that improve road safety, also referred to as safety messages and applications, respectively.
Most safety applications require disseminating messages to all the nodes (vehicles and RSUs) within one-hop transmission distance of the corresponding node. Consequently, safety messages are broadcasted such that the messages are disseminated to each one of the nodes within an area of interest, e.g., within one-hop transmission distance of the source node. The lifetime of safety messages is typically less than 100 ms within the area of interest. In addition, substantially all nodes, for example at least 99% of nodes, in the area of interest must receive safety messages. Vehicular networks require a reliable and efficient one-hop broadcast service from its medium access control (MAC) layer protocol to successfully deploy safety applications that have stringent quality-of-service (QoS) requirements. Therefore, safety applications generally have strict QoS requirements, i.e., high communication reliability and strict delay constraints. For example, to meet the strict QoS requirements, it will be necessary for a message to reach at least 99% of the target destination nodes within 100 ms. This standard may be difficult to meet due to the dynamic networking conditions in vehicular networks.
The forgoing creates challenges and constraints for establishing and maintaining reliable vehicular communications among nodes in VANETs. There is therefore a need for a method and system of rebroadcasting messages for reliable vehicular communications in order to meet the strict QoS requirements. It is an object of the present invention to mitigate or obviate at least one of the above mentioned disadvantages.